First Trimester Screening



Deborah explains the Nuchal Translucency Scan

More information about First Trimester Screening:

The Ultrasound Suite along with the Bray Women’s Health Centre offer First Trimester Screening as a combined package. Please note that this package can only be booked by phoning Bray Women’s Health Centre reception on 012761522. We advise you to book at least 2-3 weeks in advance to avoid potentially long waiting lists.

Accuracy and timing for First Trimester Screening

We use a system, recommended by the Fetal Medicine Foundation, whereby the blood tests are carried out at 10 weeks and the scan is performed at 12 weeks. It has been estimated that this approach increases detection rates up to 94%. This requires 2 separate visits but we feel that it is important to achieve the highest accuracy that we can. (If you are unable to plan your appointments this way, the blood tests can be performed 9 weeks 0 days – 13 weeks 6 days, and the scan can be performed 11 weeks 2 days – 13 weeks 6 days).

If you decide to book the scan on its own (without the blood tests), the accuracy is about 75%. You can book the scan through our online booking system.

10 weeks 12 weeks 94%
11 weeks 11 weeks 92%
12 weeks 12 weeks 84%
13 weeks 13 weeks 80%
No blood tests 12 weeks 75%


All women have a small chance of having a baby with a physiological disability or syndrome, such as Down Syndrome. The First Trimester Pregnancy Scan Screening Package is a risk assessment test to determine whether your chances of having a baby with Down Syndrome (Trisomy 21), Edward’s Syndrome (Trisomy 18) and Patau Syndrome (Trisomy 13) are high or low.

The components of First Trimester Screening include:

  • Maternal age
  • Presence or absence of major fetal abnormalities on ultrasound
  • Nuchal Translucency (fluid measurement behind the fetus’ neck)
  • The level of two proteins in your blood (Free-ß-hCG and PAPP-A)


Please feel free to give us a call and request to speak to a sonographer if you have any questions about the Nuchal Translucency Scan or First Trimester Screening.